Is it possible, with a high-level study of grammar and a deep knowledge of the terminology used in whatever area you intend to translate in (obviously not in medicine or law, where such things are thankfully controlled by legal bodies), to self-teach into becoming a professional translator in this day and age? In particular, I am asking for Guatemala (though US answers are also welcome).
I think that restricting your option to only professional translator you seriously limit your chances of succeeding.
Far better approach will be IMHO to learn the best L2 you can, and find a job in area where you can use it performing other duties: hospitality industry, foreign trade, etc. This will pay the bills while you cover the gap: your skills growing from average to pro level, while using the L2 of your choice often to master it.
You might find you like your job and want to keep it, or decide to take the plunge and become full time translator (which might have periods of frenzy activity mixed with long periods of no activity and no income).